1. Field of the Invention
The present invention relates to an active matrix display apparatus having light-emitting elements as pixels, a method of driving such an active matrix display apparatus, and an electronic apparatus incorporating such an active matrix display apparatus.
2. Description of the Related Art
Display apparatus, e.g., liquid crystal display apparatus, have a number of liquid crystal pixels arranged in a matrix. The intensity of incident light that is transmitted through or reflected by each of the pixels is controlled depending on image information to be displayed for thereby display an image based on the image information. The above principle of operation also applies to organic EL (electroluminescence) display apparatus which having organic EL elements as pixels. Organic EL elements are self-emission elements unlike the liquid crystal pixels. Therefore, the organic EL display apparatus provides better image visibility than the liquid crystal display apparatus, need no backlight, and have a high response speed. In addition, the organic EL display apparatus are widely different from the voltage-controlled liquid crystal display apparatus in that they are current-controlled by controlling the luminance levels (gradations) of the light-emitting elements with currents flowing therethrough.
As with the liquid crystal display apparatus, the organic EL display apparatus are classified into the simple matrix type and the active matrix type. Although the former type is simple in structure, it makes it difficult to construct large-size, high-definition display apparatus. At present, therefore, efforts are mainly directed to the development of active matrix organic EL display apparatus. According to the active matrix type, the currents flowing through the light-emitting elements in respective pixel circuits are controlled by active elements, generally thin-film transistors (TFTs), disposed in the respective pixel circuits. Active matrix organic EL display apparatus are disclosed in the following patent documents, Japanese Patent Laid-Open Nos. 2003-255856, 2003-271095, 2004-133240, 2004-029791, 2004-093682, and 2006-215213.